This Research Findings provides two sets of estimates of health insurance coverage for non-elderly adults, ages 18 to 64, in the U.S. civilian noninstitutionalized population. The first set includes the percentages of non-elderly adults who were uninsured for the entire calendar year for each year from 2013 to 2015. The second set includes transitions in coverage over the two years that MEPS respondents participate in the survey, comparing gains and losses in health insurance coverage in the periods from 2013 to 2014 and 2014 to 2015 to those in 2012 to 2013.